


Under The Sea

by assbuttsinlove



Category: Supernatural
Genre: Alternate Universe - The Little Mermaid, Fluff, M/M, merman!Dean, merman!cas
Language: English
Status: Completed
Published: 2014-03-16
Updated: 2014-03-16
Packaged: 2018-01-15 23:16:06
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 3,202
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1322899
Author URL: https://archiveofourown.org/users/assbuttsinlove/pseuds/assbuttsinlove
Summary: <blockquote class="userstuff">
              <p>For a long time, Prince Castiel’s grotto where he kept all his hidden trinkets and treasures had been his most heavily guarded secret.  Now, his biggest secret was Dean, the sweet, green-eyed palace guard, with the freckles.  Castiel doesn't know how to tell Dean how he feels, so instead, he tries to show him.</p>
            </blockquote>





	Under The Sea

**Author's Note:**

> written for the deancasweek2014 challenge. loosely based upon the little mermaid. set in their universe.

Castiel had always been good at keeping secrets. 

He had many secrets of his own, and he worked diligently to make sure that none of them saw the light of day.  For a long time, his biggest secret had been the hidden grotto where he hoarded his treasures. He had discovered it with Flounder years ago, hiding one night from a pack of sharks that had been on his tail.  He had easily slipped into the crack and had hidden from the sharks until they passed. It was only when they were long gone, did he discover the cavernous space behind him.    

Since then it had become his place of refuge.  Whenever he found something new, some odd trinket floating down from the world above, or something he scavenged from a sunken ship, he would quickly slip away and race to the grotto where he would hide it, safe, from prying eyes.  The only other living soul to see the inside of the grotto had been Flounder and he intended to keep it that way.

Now, all these years later, he still went to his hideout, perhaps with less haste than he did when he was younger.  He would still lovingly run his hands along all the strange contraptions, the silver instrument with the prongs that he sometimes ran through his hair.  The odd little pipe that produced bubbles when he blew into the spout.  He had found little things that looked like the humans above, girls, soft, with legs and eyes that had been sewn on with threads.  Many of them had rotted over the years and he would see the little fragments of cloth floating around in the water like the stars in the night sky. 

For a long time, Castiel’s grotto had been his most heavily guarded secret.

Now, his biggest secret was Dean.

Dean, a young palace guard, with freckled skin and green eyes.  He was shy, with a sweet smile, and a dark green tail, and usually guarded one of the outer walls of the palace, though he sometimes did patrols. 

Cas had been swimming, off exploring, shirking his responsibilities (as per usual) and he had ventured too far, drifted past the border without even noticing. He had only realized it when it was too late, and he was already ensnared in a strange web, a net of some kind that seemed to squeeze him even tighter the more he struggled. He had been on the brink of passing out, slowly fading into darkness when Dean had found him and cut him loose. He had dragged him back, away from the mysterious net and back to where it was safe and tended to his wounds.

Since then, they had been inseparable, and Cas went to visit Dean as often as he could, even though it was difficult for them both, with Dean being a palace guard, always patrolling, and Cas being one of the crown princes, always under the watchful eye of his father, the king.  Yet try as Triton might, he could not watch Castiel all the time, and as soon as he was free, he slipped away from the castle and swam down to the outer edges to seek out his new friend, Dean.     

Today, Dean was staring out into the distance, a somewhat wistful expression on his face.

The sun was setting above them setting the water aflame.  Cas hovered off to the side, in a small alcove where he was hidden from anyone’s gaze but Dean’s. 

“You seem pensive,” Cas murmured. 

Dean looked over to him and shrugged, tightening his grip on his spear.  “Don’t you ever get tired of it all?” he asked.

Cas frowned. “Of what?”

Dean gestured to the castle, to its walls.  “Of _this_ , of this life…I mean…don’t you ever want to know what’s happening in other places? Don’t you want to swim in other seas?” he asked. 

Cas chuckled and swished his tail.  “Quite often, yes,” he said.  “What’s bringing this on?” he asked. 

Dean sighed and shook his head.  He stared out into the distance, falling quiet for a few moments.  “I always think about it…I just never really had anyone to tell,” he said with a small smile. 

Silence fell between them once more and Cas looked up toward the surface. “Have you ever been up there?” he asked quietly.

Dean shook his head.  “No…we’re not allowed to, you know that,” he said. 

“So you’ve never seen the stars?” Cas asked, shocked. 

“No…have you?” Dean asked.

Cas smiled and nodded.  “They’re _beautiful_ , Dean,” he said breathlessly.

Dean smiled and looked up. 

“They remind me of…well, your freckles remind me of them,” Cas said quietly.

Dean turned to him, a blush stealing across his cheeks.  “ _Really_?” he asked, his voice soft. 

Cas blushed and nodded.  He observed Dean and the way he held his back straight, the way he held his spear, his hand curled around the wood.  He watched as Dean’s tail swished gently back and forth.  He suddenly realized that even though he and Dean had been meeting like this for a while, he had never swum with Dean…he hadn’t gotten the chance to do much with Dean apart from this and for the first time...he wanted more. 

“Dean?” Cas said.

Dean turned his head and smiled.  “Yeah, Cas?” he asked. 

“Will you meet me tonight?” he asked.

Dean froze and his tail stopped moving.  “What?”

Cas smiled and leaned forward, his own tail swishing excitedly.  “Will you meet me tonight when your watch is over? I want to…show you something,” he said. 

Dean flushed and gripped onto his spear even tighter.  “Do you think…I mean, we could get in trouble, Cas.  At least I can…I mean you’re a prince I’m just a…a nobody,” he said softly. 

Cas frowned and angrily swam out of the alcove.  “You’re not a nobody, Dean…” he said. 

Dean scoffed and looked away.  “Yeah, I am…I’m just another faceless guard, just like the rest of them…what makes me any different?” he snapped. 

Cas stared at him for a moment and then floated over to him.  He looked around for a quick moment before leaning forward and gently cupping Dean’s face in his hands. 

Before Dean could react, Cas had crossed into his personal space and was pressing his mouth against his lips in a searing kiss.  His grip on his spear loosened and it fell to the ground with a soft thud.  He reached up and placed his hands on Cas’ arms, leaning into the kiss, enjoying the feel of Cas’ mouth pressed up against his own.  He knew what could happen to him if they got caught or were seen, he could be banished, killed even, but as he felt Cas’ tail curl and brush up against his, he realized that he didn’t care. 

Slowly pulling back, Cas brushed Dean’s cheekbones with his thumbs.  “You’re different, trust me…” he whispered.

“Cas we could get into a lot of—”

“Trouble, I know,” he muttered.  He moved away, bending over to pick up Dean’s spear, and handed it to him.

“It’s not that I don’t want to—”

“Shut up, Dean.  Will you meet me tonight or not?” Cas asked, his blue eyes twinkling mischievously.

Dean sighed. “Fine, where?” he asked.

Cas grinned at him and ran a hand through his hair.  “Meet me at the sunken ship…give me two hours, I’ve got to put in an appearance at court at least to get my father off my back for the rest of the night,” he said, rolling his eyes. 

Dean laughed and nodded.  “All right,” he said.

Cas swished his tail happily and began to swim away. 

Dean watched him as he left, and though his heart and face felt pleasantly warm, and his lips still tingled from where Cas had kissed him, his stomach was tied up into knots. What they were doing was dangerous and Cas knew it. 

The biggest question on Dean’s mind was whether Castiel was worth the risk.

He gently brushed his fingers against his lips and a small smile bloomed on his face.

Quite suddenly knew the answer to his question.

* * *

Castiel adjusted the cloak around his shoulders and fiddled with his hood. He hated wearing these things, and much preferred to swim around without it, but at this hour, he needed the extra coverage.  Especially since he would be swimming through the marketplace.  The last thing he needed was some overzealous palace guard catching him in the wrong place at the wrong time.  He swam through as quickly as he could keeping to the shadows until he arrived at the stone archway that led out into the open. His heart pumped wildly in his chest as he zoomed past other merfolk and made his way even further out on the fringe where the sunken ship lay rotting in the deep. 

The nearer he got to the ship, the quieter it became.  Merfolk hardly ever visited the carcasses of the ships, there was nothing to see, and many of the old folk had dubbed them unsafe, so as a general rule, the area was left clear.  That never stopped Cas, of course.  As soon as he was able to leave the palace on his own, the ships had been his first destination.  It was where he had discovered many of his treasures, some of which he hoped to show Dean tonight.  He slowed down as he approached the largest ship, and he tossed back his hood, searching around for Dean.  The ship was illuminated by the light of the moon, streaming through the water and it produced an eerie effect. 

“Dean?” he said cautiously. 

He was startled by a soft swish, and when he turned around, Dean was behind him, also donning a cloak and hood.  In his right hand he held a spear, though a smaller one, and he pushed back his hood, revealing a large smile. 

“You made it,” Cas said excitedly. 

Dean blushed and nodded.  “Yeah,” he said.

Cas smiled and swam over to him, his tail moving happily in his wake.  He took Dean’s hand in his own and pulled him forward. “Come,” he said.

With a nod, Dean allowed Cas to guide him through the sunken graveyard. The two of them took off, leaving a trail of bubbles behind them. 

“Where are we going, Cas?” Dean asked looking over at him. 

Cas grinned and shook his head.  “It’s a secret,” he said.

He tightened his grip on Dean’s hand and swam faster. 

* * *

“What in the world is this thing?” Dean asked, his eyes wide as he spun the strange orb around with the tips of his fingers. 

Cas swam over to him and touched the surface of the orb.  Moonlight filtered down through an opening at the very top of the stone hideout and illuminated all of Castiel’s treasures.  “I’m not sure but…I think…the blue parts might be our world,” he said as he trailed his finger along a dotted line.

Dean frowned and looked at him.  “ _Our_ world? Like beneath the ocean? So what’s all these other things?  And why is it _round_?” he asked.

Castiel laughed and shrugged.  “The green things must be land, as for the shape, I have no idea,” he said. 

Dean studied it for a few more moments and then put it down, moving on to something new. He picked up a small wooden chest and tried to pry it open, only to realize that it was locked.

“I’ve been trying to open that one for a long time, I gave up,” Cas said with a laugh.

Dean hummed thoughtfully and began to swim around, searching for something with the box tucked securely under his arm. 

Castiel watched him with a small smile on his face as he floated around the grotto, searching for something presumably to pry the box open.

He settled on a thin piece of hard metal, and set to work on breaking the lock. Within moments, Dean had somehow managed to do what he himself had been trying to do for months and he looked up at Cas and grinned.  “Your treasure box,” he said as he presented it to Cas. 

Cas floated over to him and sat next to him.  He took the box in his hands, heart pounding and eager to finally see what was inside, but then he stopped.  “Wait…no, you should open it, you’re the one who cracked the lock,” he said.

“Really?” Dean asked in a soft voice.

Cas nodded and handed the box back to him. 

Slowly, with a shaking hand, Dean lifted the cover and they both gasped. Nestled inside were countless jewels, all of them shimmering in the moonlight.  He reached in and pulled out a long string of pearls and giggled. “This is beautiful,” he said reverently.

Cas reached out and took them from him, slowly running his fingers along the pearls. He leaned forward and roped them around Dean’s neck, smiling as they settled against his chest. “They look good on you,” he said.

“Why thank you, Prince Castiel,” he said with a wink.  He reached into the box and extracted a small tiara which he daintily placed on Cas’ tuft of dark hair.  Next, they found rings, and they laughed as they slipped them onto each other’s fingers.  “Why do you have all these things here, Cas? I mean…this is great stuff…it should be in the palace on display,” he said as he closed the box and put it to the side. He picked up a strangely shaped object, crafted out of wood and glass with sand on the inside.

Cas shook his head and snorted.  “Do you really think my father would approve of any of it?” he asked bitterly.  

Dean put the strange contraption down and he turned to face Cas.  “I think it's is great, like you,” he said with a blush.

Cas inched closer to Dean and they nuzzled their noses together. 

Dean closed his eyes and moaned softly when Cas kissed him.  He reached up to curl his fingers in Cas’ hair and sighed happily.  Here he was, kissing a prince.  When they pulled back, they were both flushed and their tails were fluttering happily. “Hey…have you ever heard that old story about the princess who kissed the clam and he turned into a prince?” he asked. 

Cas laughed. “Of course.”

“Will you turn into a clam if I keep kissing you?” he teased. 

Cas shrugged. “I guess we’ll just have to keep kissing to find out, right?” he asked. 

Dean laughed and fiddled with his pearls.  “Cas…I don’t want to….I don’t want this to sound strange but…what _are_ we?” he asked. 

Cas pondered on this for a moment and then he sighed.  “I wish I knew, Dean,” he replied. He reached out and took Dean’s hand in his own.  He didn’t know what he and Dean were but he knew how Dean made him feel.  He was like the calm after the storm…the gentle breeze…when Cas looked at Dean, he felt that same awe and breathlessness like when he poked his head above the surface at night to study the stars above them. “I want to show you something else…” Cas said softly.  He gently tugged on Dean’s hand and pulled him up. 

“I can’t tell you _what_ you are to me, Dean,” Cas said as they continued to swim up.  “But I can show you how you make me feel,” he said. 

They continued to swim, Cas clasping onto Dean’s hand tightly, swimming faster and faster up to the surface. 

Just before they got up to the top Dean stopped.  “Cas…wait…what are you doing?” he asked. 

“Trust me, Dean.”

“Cas—”

“Dean…it’s okay, I promise,” he said. 

Dean swallowed thickly and then nodded. 

Slowly, Cas pulled him closer to the surface and together, they broke the water and just like that, they were on the other side. 

Dean took in a breath through his nose and mouth and he thrashed around for a moment.

Cas reached out and gently placed his hands on his shoulders, calming him down. “Dean, Dean relax!” he said with a laugh. 

Dean closed his eyes and took a deep breath.  Slowly, he opened them again and Cas was staring at him.

“Are you okay?” he asked. 

Dean blinked and nodded.  “Yeah…yeah I’m….oh my God,” he said softly.  He looked around and there were miles and miles of smooth water around them. “I’m here…I’m…Cas…” his voice broke and he felt tears burn at the corner of his eyes. 

Cas nodded and tilted his head back.  “Look, Dean,” he said quietly.

Dean looked up into the sky and let out a soft gasp.  It was large, bigger than anything he had ever seen, and it was black, and deep and if Dean could say what the word forever looked like, this would be it.  But perhaps the most beautiful part of the sky were the stars, all of them shining so brightly like countless little diamonds.  High in the sky the moon was hanging low, ripe and full, bathing them in a cold white light.  Everything was still and beautiful and the only thing Dean could feel was the rapid beating of his heart in his chest.  He was so overwhelmed by it all, he didn’t even bother to hide the tears as they fell from his eyes. 

Cas, who had seen the stars far too many times, chose to stare at Dean instead, and bask in the look of awe on his face.  “This is how I feel Dean, when I look at you, when I’m next to you,” he whispered.

Dean looked over at Cas, wiping away tears.  “Really, Cas?” he asked. 

Cas nodded and floated closer to him. 

“I’ve been…trying to figure out how to describe the feeling I get when I’m with you and…this is it, Cas…it feels like…forever,” he said. 

Cas lightly grasped onto the pearls around Dean’s neck and pulled him close. “I want us…forever, Dean,” he whispered. 

Dean blushed. “Me too, Cas…” he murmured. “But what about…the king I mean…this isn’t…exactly…you know…”

Cas laughed and shrugged.  “We’ll cross that chasm when we get to it,” he said. 

Dean leaned in for a kiss and Cas stopped him. 

“Wait,” he said.

Dean frowned. “What is it?” he asked.

“Just…promise me you won’t turn me into a clam,” he whispered.

Dean laughed softly and then nodded.  “Deal.”

“Excellent,” Cas replied.  He leaned in for a kiss and smiled against Dean’s mouth. 

When they broke apart, they entwined their fingers together and stared up at the stars, pointing out the strange formations they saw and wondering what they meant.  When Cas looked over at Dean, he felt something stir in his chest and suddenly he knew that he had found the greatest treasure of them all. 

Dean caught him staring, and smiled.  “Forever?” he asked softly.

Cas grinned and squeezed Dean’s hand.  “Forever.”   


End file.
